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Werner Tjarks, Dr. rer. nat.

Associate Professor,
Division of Medicinal Chemistry & Pharmacognosy

Parks Hall Room 421
500 West 12th Avenue
Columbus, OH 43210

E-mail: tjarks.1@osu.edu
Phone: (614) 292-7624


Education


Areas of Interest

Nucleosides for anticancer, antiviral, and antibiotic therapies

Nucleoside antimetabolites such as gemcitabine, cytarabine, cladribine, fludarabine, clofarabine, acyclovir, ganciclovir, brivudine, zidovudine, stavudine, and emtricitabine are prodrugs that are widely used as anticancer agents or antiviral agents and their importance continues to increase. These antimetabolites utilize nucleoside salvage pathways for their transformation into active nucleoside triphosphates. Irrespective of the final intracellular targets of the triphosphates, which primarily are human or viral DNA and their respective polymerases or reverse transcriptases, the rate-limiting key activation step of the prodrugs is usually the initial conversion of the nucleoside to the corresponding monophosphate by phosphorylating enzymes, often deoxynucleoside kinases. Thymidine kinase (TK) is one of these deoxynucleoside kinases. Most eukaryotes and prokaryotes and many DNA viruses code for proteins with thymidine kinase activity. However, among all approved nucleoside antimetabolites only the HIV prodrugs zidovudine and stavudine are activated by human thymidine kinase 1 (hTK1). This is probably due to the fact that TKs have the most stringent substrate specificity among all nucleoside kinases and that crystal structures for drug design have only become available very recently. Dr. Tjarks’ research activities focus on the in silico design, synthesis, and biological evaluation of inhibitors and substrates of TKs from e.g. Bacillus anthracis and Epstein-Barr virus as well as from hTK1 for antibiotic, antiviral, and anticancer therapies.

A second research focus of Dr. Tjarks’ group is the synthesis of boron and lanthanide containing porphyrin-type macrocycles, which could be considered as “multipurpose” anticancer diagnostics and therapeutics. Due to their unique intrinsic properties boron/lanthanide containing porphyrin-type macrocycles could serve as MRI contrast agents, near-infrared imaging agents, neutron capture therapy (NCT) agents, radiationsensitizer, photosensitizer, and cancer chemotherapeutics.

A third research focus of Dr. Tjarks' group is the synthesis of boron and gadolinium containing compounds that are utilized for the construction of tumor-targeted liposomes and nanoparticles for Neutron Capture Therapy of Cancer. Targeted cellular receptors include the vascular endothelial growth factor receptor (VEGFR), the epithelial growth factor receptor (EGFR), and the folate receptor (FR).


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